package com.easy.util;

import java.util.Map;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ExpiryMap {

    //
    private  java.util.Map<String, Object> map = new java.util.HashMap<>();
    //存放过期时间
    private Map<String, Long> expiryMap = new java.util.HashMap<>();
    //检查过期线程(池)
    private ScheduledExecutorService service= Executors.newSingleThreadScheduledExecutor();
    //检查周期
    private long expiryTime = 1000 * 6 ;
    public ExpiryMap(){
        service.scheduleAtFixedRate(this::clearExpiry,expiryTime,expiryTime, TimeUnit.MILLISECONDS);


    }
    //带过期时间的构造方法
    public ExpiryMap(long expiryTime){
        this.expiryTime = expiryTime;
        service.scheduleAtFixedRate(this::clearExpiry,expiryTime,expiryTime, TimeUnit.MILLISECONDS);

    }

    public void put(String key,Object value){
        map.put(key,value);
        expiryMap.put(key,System.currentTimeMillis() + expiryTime);
    }
    public void put(String key,Object value,long expiryTime){
        map.put(key,value);
        expiryMap.put(key,System.currentTimeMillis() + expiryTime);
    }
//获取value
    public Object get(String key){
        if(expiryMap.get(key)!=null&&expiryMap.get(key) < System.currentTimeMillis()){
            map.remove(key);
            expiryMap.remove(key);
        }
        return map.get(key);
    }
//删除key
    public void remove(String key){
        map.remove(key);
        expiryMap.remove(key);
    }
//判断key是否存在
    public boolean containsKey(String key){
        if(expiryMap.get(key)!=null&&expiryMap.get(key) < System.currentTimeMillis()){
            map.remove(key);
            expiryMap.remove(key);
        }
        return map.containsKey(key);
    }
    //清除掉过期的key
    public void clearExpiry(){
        for(String key : expiryMap.keySet()){
            if(expiryMap.get(key)!=null&&expiryMap.get(key) < System.currentTimeMillis()){
                map.remove(key);
                expiryMap.remove(key);
            }
        }

    }
}
